Publisher : Springer, Berlin, Heidelberg
Place of publication :
Publication year : 2015
Thematic : Biodiversity
Language : English
Note
The biological community of a river ecosystem is determined by the characteristics of both terrestrial and aquatic ecosystems. The terrestrial ecosystem depends mainly on the plant community and the aquatic ecosystem comprises aquatic plants, benthic invertebrates, and vertebrates. The main ecological functions of rivers are habitat, conduit, filter, barrier, source, and sink. Ecological stresses are defined as the disturbances that bring changes to river ecosystems. The ecological stresses are natural events or human-induced activities that occur separately or simultaneously. The structure of a system and its capability of carrying out important ecological functions may be changed by stresses, regardless of whether they act individually or in combination. Damming, gravel and sand mining, channelization, water diversion, habitat fragmentation, exotic species, landslides and debris flows, and intensive fluvial processes are the most common stresses on stream ecology.
For quantitative assessment of river ecology indicator species are selected, which are defined as a set of organisms whose characteristics are used as an index of attributes or environmental conditions of interest, which are too difficult, inconvenient, or expensive to measure for other species. Benthic invertebrates and fish are used as indicator species for most stream ecology assessment. The ecosystem can be assessed by monitoring the species richness (number of species) and the number density (or abundance) for each species. Many parameters representing biodiversity of river ecosystems have been proposed. Management and restoration of river ecosystems are based on an understanding of the relations between physical, chemical, and biological processes at varying time scales. Often, human activities have accelerated the temporal progression of these processes, resulting in unstable flow patterns and altered biological structure and function of stream corridors. Various strategies for ecological restoration are discussed in this chapter.
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Keywords : biodiversity
Encoded by : Pauline Carmel Joy Eje
